Display screen or portion thereof with transitional graphical user interface



FIG. 1 is a front view of the first image in a sequence of a display screen or portion thereof with transitional graphical user interface, showing our new design in a first embodiment;

FIG. 2 is a front view of the second image thereof;

FIG. 3 is a front view of the third image thereof;

FIG. 4 is a front view of the first image in a sequence of a display screen or portion thereof with transitional graphical user interface, showing our new design in a second embodiment;

FIG. 5 is a front view of the second image thereof; and,

FIG. 6 is a front view of the third image thereof.

The appearance of the transitional graphical user interface sequentially transitions between the images shown in FIGS. 1-3 and 4-6. The process or period in which one image transitions to another forms no part of the claimed design.

The broken lines in the FIGS. 1-3 depict portions of the display screen or portion thereof with graphic user interface that form no part of the claimed design. The outer broken lines in FIGS. 4-6 depict the display screen or portion thereof that forms no part of the claimed design. The remainder of the broken lines in the FIGS. 4-6 depict portions of the graphical user interface that form no part of the claimed design. 

CLAIM The ornamental design for display screen or portion thereof with transitional graphical user interface, as shown and described. 